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Biomedical subjects

A Lindner

Publications and source records attributed to A Lindner.

At least 127 records · Page 7Linked to original sources

Increased cytosolic free calcium in red blood cells is associated with essential hypertension in humans.

Intracellular free calcium (Cai2+) was measured in human red blood cells (RBCs) using the Ca(2+)-sensitive fluorescent probe, fluo-3. Fresh RBCs were loaded with the acetoxymethyl ester of fluo-3 (fluo-3-AM) in vitro. Following incubation at 37 degrees C for 60 min, cells were separated from nonincorporated fluo-3-AM and fluo-3. Fluorescence was quantified with excitation and emission wavelengths of 506 nm and 526 nm, respectively. The relatively long wavelength characteristics of fluo-3 avoid much of the interference from hemoglobin that makes agents such as quin-2 and fura-2 of limited value in RBCs. A protocol with corrections for quenching and for extracellular fluo-3 was employed for each sample. Cai2+ in red blood cells from 15 normotensive volunteers averaged 134 +/- 12 nmol/L. In RBCs from 30 hypertensive patients who were not treated pharmacologically, Cai2+ was 317 +/- 32 nmol/L (P < .05). In a group of 27 hypertensives who were treated with various drugs, RBC Cai2+ was 221 +/- 27 nmol/L. Measurements were also performed in RBCs from 16 patients before and at least 2 weeks following treatment with one or more antihypertensive agents. Reduction of RBC Cai2+ from 342 +/- 47 to 252 +/- 39 (P < .001) was observed in 16 patients whose blood pressure fell with treatment. Overall, there was a correlation between RBC Cai2+ and diastolic blood pressure (r = 0.413, P < .01, d.f. = 71). Thus, the present results confirm an association between elevated RBC Ca2+ and essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effect of temperature, duration of storage and sampling procedure on ammonia concentration in equine blood plasma.

The effect of storage duration at different storage temperatures on the plasma ammonia concentration of equine EDTA whole blood, EDTA plasma and heparin plasma samples was investigated. Further, the effect of jugular vein compression before and during blood sampling on the plasma ammonia values was evaluated. In EDTA whole blood kept at 4 degrees C there was no significant increase of ammonia content after 6 hours of storage, whereas the increase was already significant 3 hours after collection if the EDTA whole blood was kept at 20-22 degrees C. EDTA plasma samples stored at 20-22 degrees C, 4 degrees C and -20 degrees C showed mean ammonia formation rates of 26.8 mumol/l, 6.6 mumol/l and 0.03 mumol/l per day, respectively. There were no differences between ammonia values of EDTA and heparin plasma samples immediately after sampling and following 3 days of storage at 4 degrees C and 3 and 90 days of storage at -20 degrees C. Although significant, the absolute differences between the mean plasma ammonia contents of EDTA blood sampled with and without compression of the jugular vein were small (20.2 +/- 4.1 mumol/l and 23.4 +/- 4.3 mumol/l resp.).

Ammonia↗

Imaging of the vertebrobasilar system by transcranial color-coded real-time sonography.

The vertebrobasilar system was investigated in 75 persons by TCCS to evaluate the applicability and diagnostic capacity of this transcranial Duplex technique. Transforaminal and transtemporal acoustic windows were employed to identify the vertebral arteries, basilar artery (PCA) and major branches of the vertebrobasilar system. The frequency of identifying the basilar artery and the PCA ranged from 84 to 94% but was poor for the distal segment of the basilar artery (45.3%). The origin of the basilar artery was disclosed by transcranial Duplex sonography at an average depth of 7.0 cm (range 6.0 to 8.0 cm). The assignment of the obtained flow signals to specific vascular segments was improved by this new technique. In addition, four persons received a maximum of six intravenous injections of a transpulmonary stable sonographic contrast agent (SHU 508 A) to enhance Doppler signal intensity derived from the vertebrobasilar system. The vascular trunk and all major branches of the vertebrobasilar system were identified in these four persons. We conclude that TCCS of the vertebrobasilar system will improve reliability of transcranial sonographic examination.

Basilar Artery↗

[Reproduction data in breeding mares, diseases and losses among suckling foals and preventive husbandry in German stud farms].

By means of a survey, the reproductive rate of mares and the foal losses in ten Thoroughbred, Saddlebred and Pony studs in Germany, mainly from North-Rhine-Westfalia, were collected and evaluated. Data for the survey were recorded for 1985-1990. The study also examined the hygienic management in the surveyed studs, and the morbidity rate of suckling foals was obtained for 1990. In addition to the survey questionnaire each stud was visited once. Two studs of each horse group were visited several times every week from March to August in order to evaluate as exactly as possible the husbandry and morbidity of the suckling foals. The main results were: The abortion rate in Thoroughbred and Saddlebred horses was about 4.5%, of the Ponies 1%. After the 299th day of gestation, fetal mortality ranged from 3.2 to 3.5%. In the more intensively observed studs 33% of Thoroughbred foals, 42% of Saddlebred foals and 11% of Pony foals became ill. Saddlebred foals were more frequently affected by respiratory disease while Thoroughbred and Pony foals were mainly afflicted by diarrhea. The scope of husbandry measures was broader and more intensive in the Thoroughbred and Pony studs compared to the Saddlebred studs.

Abortion, Veterinary↗

[Recurrent intermittent priapism following priapism].

Recurrent intermittent priapism is a rare sequela of prior priapism. We describe a patient with recurrent intermittent priapism 2 years after a prior event, without other causes of secondary priapism. We believe that this syndrome may be secondary to the initial ischemic event, resulting in alteration in penile adrenergic tone or the penile sinusoidal endothelium.

Adult↗

[Development of an enzyme-linked immunosorbent assay for the detection of antibodies against bovine herpesvirus type 5 (BHV-5) in sheep sera].

The indirect enzyme-linked immunosorbent assay (ELISA) was first developed for the detection of antibodies against BHV-5 in sheep sera. Investigations of various antigen (Ag) preparations revealed that BHV material which had been purified across a sucrose gradient using sonification followed by ultracentrifugation gave satisfactory results during application in ELISA. Optimal coating of the solid phase was achieved with Ag adsorption at 4 degrees C overnight with 5 micrograms of virus material/ml in a carbonate-bicarbonate-buffer, pH 9.7. The background reactions were significantly reduced by blocking the free bonding points with 1% gelafusal after Ag adsorption. As the extinction values of all the sera investigated which a dilution of 1:50 or more below 0.2, the difference threshold between positive and negative sera was set at 0.2. A total of 490 sera from various stocks of sheep were investigated with regard to the occurrence of antibodies against BHV-5 in ELISA. The growing rate of infection with herpesviruses among ruminants and the subsequent economic loss have resulted in the increased significance in the last few years of bovine herpes-virus (BHV) disease.

Animals↗

[Comparative studies of the detection of antibodies against BHV-5 using the enzyme-linked immunosorbent assay, serum neutralization test, cell assay and immunofluorescence test].

A comparison of the analyses of 490 serum samples from various flocks of sheep for the detection of BHV-5 antibodies using ELISA, serum neutralisation test, cell assay and immunofluorescence assay showed nearly identical results regarding the distinction between positive and negative serum samples. The percentage of serum samples with antibodies against BHV-5 antigen differed from test to test: ELISA 268 (54.7%), cell assay 323 (65.8%), immunofluorescence assay 222 (46.6%) and serum neutralisation test 221 (45.1%). With ELISA, cell assay and immunofluorescence assay the experiment can be carried out more simply and rapidly than with serum neutralisation test.

Animals↗

[Comparison of the career profiles of racehorses over three decades].

To compare the career profiles of thoroughbred racehorses in Germany in different decades all horses which raced for the last time in the years 1966/67, 1976/77 and 1986/87 were selected from the annual report of the German Thoroughbred Racing Association. The number of racing horses increased within decades while the percentage of the horses which raced for the last time was equal in all years. It amounted yearly to about 30%. Most of the horses finished racing at three and four years of age. In 1966, 1967, 1976 and 1977 more than 50% of the horses began their career at the age of two years, while in 1986 and 1987 the rate was below 50%. The duration of the career depended on the age at the first race and the gender. Colts and geldings raced an average of 3.5 and 4.3 years respectively, fillies 2.7 years. The average of races during the career remained constant during each decade at 27 and 35 for the colts and geldings respectively, while for the fillies it decreased from 24 races in 1966/67 to 20 races in 1986/87.

Age Factors↗

[Effect of a paramunity inducer on the incidence of diseases and the plasma cortisol content in Thoroughbred foals before and after weaning].

The effect of the prophylactic application of the paramunity inducer Baypamun on the incidence of diseases among foals (n = 63) in four Thoroughbred studs was evaluated. In a blind study, 38 of the foals received 2 ml of Baypamun intramuscularly while 25 of the foals received a placebo at six and four days before weaning and on the fifth day post-weaning. During the observation period of three weeks, beginning with the first and ending ten days after the last application, 7.9% of the foals treated with Baypamun (3 out of 38) suffered from respiratory infections compared to 24% of the foals treated with placebo (6 out of 25). The blood plasma cortisol concentrations were also measured in 53 of the foals of three studs before and 24 hours after weaning. The cortisol concentration increased in all the foals. However, the increase was significant only for the Baypamun treated foals of one stud while it was significant for the placebo treated foals of all studs (p < 0.01).

Adjuvants, Immunologic↗

[Effect of the storage temperature and time and the test sample materials on the LDH isoenzyme activity and protein fractions in horse blood].

The LDH-isoenzyme activities and the concentration of protein fractions did not differ among heparinized plasma and serum samples of horses. In heparinized plasma samples stored at 20-22 degrees C and -18 degrees C the LDH-isoenzyme activities and the content of the protein fractions remained constant within seven days. In contrast in heparinized blood samples the total LDH activity increased markedly after seven days of storage. This increase was shared by all LDH-isoenzymes but to different extents. While the share of LDH1, LDH2 and LDH3 decreased, the proportions of LDH4 and LDH5 increased. The concentration of the protein fractions in heparinized blood samples was not affected by storage at 20-22 degrees C for seven days.

Animals↗

[Glutathione peroxidase activity in whole blood and plasma of horses of different ages, sexes and different use].

GSH-Px activity in blood and plasma of 269 horses was determined and interrelated to age, sex, and type of use or breed. Furthermore values in blood were related to hematocrit and hemoglobin contents. Trotters and riding horses had higher GSH-Px activities in plasma as well as in blood (0.83 +/- 0.22 and 0.79 +/- 0.23 U/ml plasma or 27.2 +/- 4.3 and 24.0 +/- 7.0 U/ml blood) than Thoroughbreds in training and yearlings (0.61 +/- 0.,14 and 0.56 +/- 0.16 U/ml plasma or 20.6 2 +/- 6.9 and 24.6 +/- 4.3 U/ml blood). 3 to 6 years old Thoroughbreds had higher GSH-Px-activities than 1 to 2 years old ones. Colts and fillies did not have differing values.

Aging↗

Variability and circadian changes in home uroflowmetry in patients with benign prostatic hyperplasia compared to normal controls.

We evaluated the variability and circadian changes in consecutive measurements of home uroflowmetry in 32 patients with symptomatic benign prostatic hyperplasia (BPH) and 16 healthy men. In the BPH group 476 uroflow measurements were recorded during 24 to 72 hours (mean 14.9 measurements per patient), and the controls produced 100 flow recordings (mean 6.25 measurements per participant). Great variability between consecutive peak flow rates was observed in the BPH group, ranging from at least 1 standard deviation in 28 of 32 patients (87.5%) to at least 2 standard deviations in 15 of 32 (47%). In 21 of 32 patients (65.6%) the highest recorded peak flow rate was greater than, while the lowest peak flow rate was less than the -2 standard deviations plot in voiding nomograms. In the control group variability between consecutive voiding episodes also was marked, namely at least 1 standard deviation in 8 of 16 men (50.0%) and at least 2 standard deviations in 2 of 16 (12.5%). However, in none of the control men was any peak flow rate measurement less than the -2 standard deviations line. Circadian changes in diurnal and nocturnal measurements of voided volume, interval to maximal flow, flow time, peak flow rate and adjusted peak flow rate were recorded in the BPH group, providing a urodynamic support to a well known clinical observation.

Adult↗

A circulating inhibitor of the RBC membrane calcium pump in chronic renal failure.

A humoral inhibitor of the membrane calcium pump was studied in plasma from 28 normal controls, 33 patients receiving long-term hemodialysis, and 26 with chronic renal failure (CRF; creatinine clearance range was 6 to 97 ml/min). Calcium pump activity was measured as the rate of Sr2+ efflux in normal erythrocytes (RBCs) loaded with Sr2+ (a substitute of Ca2+ in the calcium pump). Plasma, and plasma ultrafiltrates from hemodialysis patients strongly inhibited calcium pump activity compared with controls without plasma (36 +/- 18 vs. 25 +/- 12, %INHIBITION/CONTROL, P < 0.05). Inhibition markedly decreased with acute hemodialysis (16 +/- 12 vs. 5 +/- 14, %INHIBITION/NORMAL PLASMA, N = 15, P < 0.001). In CRF, degree of inhibition correlated with the serum creatinine concentration (r = 0.75, P < 0.001). A kinetic study showed that plasma decreased the maximal rate of the Ca2+ pumps (Vmax) without affecting the apparent affinity for internal cations (KSr). Moreover, the plasma inhibitory factor had a low molecular weight, and was dialyzable and heat stable. In conclusion, we found evidence for an RBC membrane calcium pump inhibitor in uremic plasma, which correlates with the degree of renal insufficiency. Possibly, it may increase calcium content in RBCs and other cells and could thus be related to uremic toxicity and/or hypertension.

Adult↗

Transcranial color-coded real-time sonography in the evaluation of intracranial neoplasms and arteriovenous malformations.

Transcranial color-coded real-time sonography (TCCS) was performed in 57 patients with primary intracranial brain tumors (n = 49) or arteriovenous malformations (n = 8) to evaluate its diagnostic potential. In 46 patients (81%), lesions could be identified employing this technique. In 7 patients, transcranial ultrasound examination was not feasible because of bone thickness; in the remaining 4 patients, the tumor was indistinguishable from adjacent brain tissue despite sufficient insonation, suggesting that these neoplasms are isoechogenic. The sonographic features of brain tumors were very similar: a hyperechogenic matrix of the lesion was interspersed by hypoechogenic pixels. Larger hypoechogenic areas (0.5-1 cm) gave evidence of tumor necrosis. Differences between the findings of TCCS and computed tomography concerning tumor size were found in 7 patients, in whom TCCS revealed an area of smaller extension within the corresponding hypodense area on the computed tomographic scan. Perifocal brain edema could not be detected by ultrasound examination. In 13 patients, a thin, hypoechogenic peritumoral halo was disclosed that did not correlate with perifocal brain edema identified by computed tomography and that may have been due to compression of adjacent parenchyma. In patients with arteriovenous malformations, TCCS permitted the identification of the main feeders, the nidus, and the draining venous system by color-coded depiction of intravascular blood flow. In conclusion, TCCS is an additional method for initial diagnosis and highly suitable for follow-up in tumor patients and provides valuable information about tissue characteristics and blood flow.

Adult↗

[Useful life, departure rates and causes in sport horses].

A review of the operational life, attrition and lethality rates, major causes of attrition and death for thoroughbred and standardbred race horses and competition horses is given. Because of the lack of data, it was not possible to supply answers for all the sport disciplines. The operational life in sports for thoroughbred race horses was 3.3 years, for standardbred horses 4.1 and for competition horses 5.5 years. Attrition and lethality rates could be determined only for the thoroughbred race horses. The yearly rates of attrition and lethality were 30% and 2% respectively. The major causes of attrition for thoroughbreds were due to inadequate performance and breeding, for competition horses due to damages of the locomotor, respiratory and gastrointestinal systems. Damage of the locomotor system was by far the most important cause for the death of thoroughbreds while for competition horses it was the gastrointestinal, locomotor and respiratory systems. The available data was not sufficient to make an evaluation of the parameters selected.

Age Factors↗